Lipophilic alkyl caffeate synthesis using a novel green binuclear ionic liquid 1,1-bis(2-pyrrolidinone) sulfate
Xuejing Liu1, Yaoyao Zhang1, Shangde Sun1
1National Engineering Research Center of Wheat and Corn Further Processing, School of Food Science and Engineering, Henan University of Technology, Lianhua Road 100, Zhengzhou 450001, Henan Province, PR China.
Abstract:
Caffeic acid (CA), as a potential green antioxidant, plays an important role in food processing. However, the low liposolubility of CA limits its applications. To overcome this issue, CA is normally modified by introducing a lipophilic group, such as alkyl alcohols, resulting in the formation of alkyl caffeate, which can significantly enhance the liposolubility of CA. In this study, a binuclear ionic liquid, 1,1-bis(2-pyrrolidinone) sulfate ([C3(Hnhp)2][HSO4]2), is successfully synthesized and characterized by FT-IR and 1H NMR. The physico-chemical properties of [C3(Hnhp)2][HSO4]2, including the density, viscosity, thermal stability and Brønsted acidity, were analyzed. As a novel catalyst for the esterification of CA with model dodecanol, its catalytic performance was investigated and optimized by response surface methodology. Under the optimal conditions, a 95.42 ± 1.01% yield of dodecanol caffeate was achieved. Moreover, the [C3(Hnhp)2][HSO4]2 exhibits excellent stability and reusability, making it a highly promising catalyst for the synthesis of various lipophilic alkyl caffeates.
More Related Videos
06:31Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators
Published on: November 27, 2015
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Related Concept Videos
01:10α-Alkylation of Ketones via Enolate Ions
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
03:08Hydroboration-Oxidation of Alkenes
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...